Cobalt Blue Sea Glass… at a Glance

Coming in at RARE on the Sea Glass Rarity Chart, Cobalt Blue is the Darling of the Sea Glass World…

Is it because it’s the color of the sea at midnight that we love deep, vibrant, glowing cobalt blue sea glass so much? There’s just something about it that says sea and sky, and “antique” all at the same time.

Most cobalt blue sea glass does indeed come from vintage bottles and jars… we just don’t make much blue glass anymore, now that plastics have taken over the packaging world. The thickest sea glass pieces – some with internal bubbles, often come from antique apothecary and poison bottles.

Cobalt Blue Sea Glass: Top 10 Facts at a Glance

1. Yep, it is the bright blue mineral cobalt that gives cobalt blue glass its color – the more cobalt, the deeper the blue.

2. Cobalt blue sea glass, while rare, is one of the easiest colors to spot when hunting the shoreline as the color pops on both light and dark sand and rocks.

3. Cobalt blue glass has been popular since Ancient Egypt… King Tut’s death mask featured cobalt blue glass inlay.

4. Blue glass beads have been used as a form of money for hundreds of years.

5. You can still sometimes find cobalt blue sea glass pieces from poison bottles washed up on shore – they sometimes still have the slightly raised letters of the “Not to be Taken” embossing just discernable on the surface.

6. Blue glass has been associated with wealth and prosperity for thousands of years… it does have a regal look to it!

7. Cobalt blue sea glass and cornflower blue sea glass are siblings – the only difference is that cobalt blue sea glass has more cobalt in it – creating a deeper color.

8. Thinner pieces of cobalt blue sea glass are often pieces of Milk of Magnesia or Noxema bottles from the 1940s and 1950s when these companies were still using glass.

10. Only about one in 250 - 300 shards of sea glass discovered is cobalt blue.

With the advent of plastic packaging, the production of blue glass dropped dramatically, and blue glass bottles are rare today as they are used only by specialty makers for things like alcohol and perfume bottles. But the legacy of the golden age of glass bottles lives on in these tiny gifts of the sea.